FIELD OF THE INVENTION
The invention relates to a moving contact which has a sliding contact for the transmission of electrical power from an overhead power line to an electrically powered vehicle. The overhead power line can damage the sliding contact, when the overhead line is deflected vertically due to the influence of external forces. In order to prevent such damaging effects on the sliding contact, the moving contact is equipped with at least two height adjusting components to compensate for the vertical movement of the overhead line. According to the invention, one of the components is a passively sprung component and the other component has regulated height adjusting capabilities. The height adjusting components are installed between the electrically powered vehicle and the sliding contact.
Moving contacts of this general type have the object of transmitting electrical power from an overhead power line to an electrically powered vehicle. The moving contacts which have been used until now have at least one sliding contact which is in the form of a rod and whose longitudinal axis is aligned at right angles to the longitudinal direction of the overhead line. The contact between the overhead line and the sliding contact is maintained with the aid of a retaining apparatus which is configured as a rocker arm or pantograph. It is disadvantageous in this case that the moving contact, which operates in a purely passive manner, can compensate for the oscillations of the overhead line which occur at high vehicle speeds only by increasing the restoring force, and thus by increasing the contact-pressure force of the sliding contact against the overhead line. This can be achieved only by further spreading of the retaining apparatus. In this way, the risk of contact separation between the sliding contact and the overhead line can be avoided, and the formation of arcs can be reduced. However, increased material wear on the sliding contact occurs because of the greater mechanical stresses applied to the sliding contact.
The British Patent Application No. 2,088,303 A describes a moving contact and overhead line combination used to power electrically powered vehicles. The moving contact is in the form of a telescopic strut arrangement. A rocker arm, which is in contact with the overhead line, is attached to the upward-pointing end of a rocker arm support. It is pressed against the contact wire of the overhead line by a spring, a hydraulic mechanism or a pneumatic mechanism. The rocker arm support is disposed in a moving contact tube which is installed telescopically in an extension tube. The rocker arm support can be fixed at different heights by an adjusting apparatus. A further apparatus is provided by which the position of the rocker arm support in the moving contact tube corresponding to the respective height of the contact wire can be determined. If, owing to changes in the height of the contact wire, the rocker arm support comes into the vicinity of the upper or lower limit position, the height of the moving contact tube is adjusted upwards or downwards automatically.